Debris blowers are commonly used by commercial lawn maintenance companies that provide service-for-hire multi-seasonal lawn care. In the lawn maintenance industry, speed, efficiency, reliability and labor-saving means are essential for success. The debris blower has continuously filled a vital niche aiding in the dispersion or collection of debris including leaves and grass clippings. Typically, debris blowers are used to disperse grass clipping and leaves from sidewalks and driveways after a lawn cutting. Similarly, the debris blower may be used to disperse clumps of grass from the non-uniform dispersion of clippings by a lawn mower. Additionally, debris blowers are used to direct leaves and other debris into windrows or piles to aid in their collection and removal.
Debris blowers are well known in the art. Typically, debris blowers have an impeller that rotates in a plane perpendicular to a generally horizontal ground surface to direct a blast of air through a discharge chute towards or across the ground surface. These debris blowers are generally mounted to a cart. The cart is comprised of a frame on which an engine is mounted. The frame is supported by a set of wheels to permit mobility of the debris blower. The engine is attached to the impeller by a shaft projecting horizontally from the engine. The impeller is located within a centrifugal-type housing mounted to the engine. The housing consists of a center inlet opposite the shaft and a tangential outlet, typically the discharge chute. A handle assembly mounted to the frame extends upwardly and rearwardly behind the engine to control and guide the debris blower. An operator must manually move the cart to direct the debris blower.
Debris blowers mounted on a cart are limited by speed and efficiency considerations. In particular, the cart is moved manually, limiting the use of the blower to the strength and energy of the operator. A large engine is necessary to drive the impeller, but the large engine also adds additional weight. The greater the weight, the more difficult the cart is to move and the more energy that the operator must expend to operate the debris blower. Additionally, the vertically mounted impeller makes the debris blowers more difficult and awkward to move and operate. The vertical impeller and its housing results in a high center of gravity on the debris blower, making it susceptible to tipping. Similarly, the effects of precession make the debris blower difficult to move and inefficient because large amounts of energy are wasted every time the cart is moved in a manner that disrupts the impeller's vertical plane of rotation. Further, the air flow generated by the impeller can only be exhausted from the housing in a single direction. Baffles or deflectors, which reduce the force of the air flow, must be added to the discharge chute to expand the range of degrees that air exiting the debris blower can be directed at the ground surface.
Other known debris blowers are carried by an operator by hand or on the operator's back. These debris blowers are configured very similarly to the debris blower previously described, with a housing enclosing a vertical impeller mounted to a horizontal shaft driven by an engine. The vertical impeller creates an air flow that is directed tangentially from the housing through a tube that can be directed by the operator towards the debris to be dispersed. While this type of debris blower is easy to move, it must also be light-weight and compact, thereby limiting the size of the impeller and engine, and thus the amount and force of the air flow that can be generated. Additionally, use of this debris blower is limited by the speed and strength of the operator who must carry it.
Yet another type of debris blower is known in which a debris blower with a vertically mounted impeller is mounted forward or behind a tractor or lawn mower in place of a mowing deck. This self-propelled type of debris blower is very similar to the cart-type debris blower previously discussed, except that this debris blower is connected to an engine of the tractor or lawn mower and is no longer manually moved. The tractor or lawn mower engine drives the vertical impeller to generate an air flow and pushes or pulls the debris blower while an operator drives the tractor or lawn mower.
While this self-propelled arrangement alleviates some disadvantages, these debris blowers have limited application because of their configuration. This type of debris blower can only be used with a tractor or lawn mover where the mowing deck is mounted behind or in front of a chassis of the tractor or lawn mower. However, most conventional tractors and lawn mowers attach mowing decks horizontally underneath the chassis of the tractor or lawn mower. Limited clearance between the chassis and ground makes attaching a debris blower with a vertical impeller impossible. Additionally, these debris blowers require additional parts, assembly, labor, and sophistication to mate the tractor or lawn mower to the debris blower. Excess forces are also placed on the debris blower because of a high center of gravity attributed to the vertical impeller. The high center of gravity introduces additional stresses on components of the debris blower, heightening wear and leading to mechanical malfunctions. Further, the high center of gravity and precession make the debris blower awkward to maneuver, reducing the speed at which the debris blower may be operated and increasing the likelihood of tipping the debris blower and chafing or scaring the ground surface. Furthermore, like the cart-type debris mower, baffles or deflectors, which reduce the force of the air flow, must be used to expand the directions in which the air flow can be directed towards a ground surface.